unregister_netdevice: waiting for lo to become free. Usage count = 769
ref_tracker: lo@ffff88805beb85b8 has 768/768 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_hold include/linux/netdevice.h:4139 [inline]
     dst_init+0xd9/0x460 net/core/dst.c:52
     dst_alloc+0x12e/0x170 net/core/dst.c:93
     rt_dst_clone+0x58/0x680 net/ipv4/route.c:1685
     ip_mc_finish_output+0x10b/0x5f0 net/ipv4/ip_output.c:355
     NF_HOOK include/linux/netfilter.h:304 [inline]
     ip_mc_output+0x39c/0x580 net/ipv4/ip_output.c:415
     dst_output include/net/dst.h:467 [inline]
     ip_local_out net/ipv4/ip_output.c:129 [inline]
     ip_send_skb+0x12d/0x1d0 net/ipv4/ip_output.c:1491
     udp_send_skb+0xa37/0x13a0 net/ipv4/udp.c:984
     udp_sendmsg+0x19b8/0x2330 net/ipv4/udp.c:1270
     sock_sendmsg_nosec net/socket.c:730 [inline]
     __sock_sendmsg net/socket.c:745 [inline]
     ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
     ___sys_sendmsg+0x220/0x290 net/socket.c:2649
     __sys_sendmmsg+0x275/0x4a0 net/socket.c:2735
     __do_sys_sendmmsg net/socket.c:2764 [inline]
     __se_sys_sendmmsg net/socket.c:2761 [inline]
     __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2761
     do_syscall_x64 arch/x86/entry/common.c:51 [inline]
     do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
     entry_SYSCALL_64_after_hwframe+0x68/0xd2